ISPIN
ISPIN = 1 | 2
Default: ISPIN = 1
Description: ISPIN specifies whether a calculation is performed with or without spin polarization.
In spin-polarized calculations, VASP treats spin-up and spin-down electrons separately, allowing each spin channel to develop a different charge density and occupation. This is essential for magnetic systems; for nonmagnetic systems it is generally unnecessary and increases computational cost.
- ISPIN=1: VASP performs a non-spin-polarized calculation. Spin-up and spin-down electrons share a single charge density.
- ISPIN=2: VASP performs a spin-polarized collinear calculation. Spin-up and spin-down electrons are treated separately.
Spin-polarized calculations are commonly used for magnetic materials such as Fe, Co, Ni, and magnetic oxides. To initialize magnetic moments on atoms, combine ISPIN=2 with MAGMOM.
ISPIN = 2 MAGMOM = 2*5.0 2*-5.0
This example initializes two atoms with positive magnetic moments and two atoms with negative magnetic moments, which may be useful for antiferromagnetic calculations.
Mind: For noncollinear calculations, ISPIN is ignored; use LNONCOLLINEAR=.TRUE. instead.
Mind: Since VASP 6.5.0, the calculation exits with an error if ISPIN=2 and MAGMOM are used together with LNONCOLLINEAR=.TRUE.